1. Field of the Invention
This invention relates to process and apparatus for converting thermal energy from one temperature level to a higher temperature level. It further relates to the utilization of sensible heat of a hot fluid for the vaporization of a liquid at a temperature of at least approximately that of said hot fluid.
2. Description of the Prior Art
The conversion of thermal energy from one temperature level to a higher temperature level has been carried out by the use of so called heat pumps for the space heating of air. Such heat pumps utilize the work done in vapor compression to provide the increased temperature. A typical system mechanically compresses a refrigerant vapor, e.g. freon, received at one temperature and thereby raises its temperature and pressure. The compressed vapor becomes a source of heat energy at an elevated temperature which can be removed to heat or evaporate another fluid while condensing the vapor to liquid. In the operation of such heat pumps, after said condensation, the condensate is passed to an evaporator at lower pressure where it is vaporized while extracting thermal energy from a suitable heat source, e.g. outdoor air or surface or subsurface water, and the low pressure vapors from the evaporator are pumped by the compressor and recycled. Such source of heat has been employed to warm air in air conditioning systems and the equipment used often is the same refrigeration system as that used for air cooling. Vapor compression has also been used in connection with industrial processes involving boiling, e.g. evaporation and distillation, to recover and recycle heat of vaporization by compressing the vapors to a higher temperature and pressure and employing the compressed vapors as the heat source in a regenerative boiler. An undisclosed proprietary temperature booster requiring a supply of cooling water has been reported by the Battelle Memorial Institute as having been tested and being available by it for use in industrial applications involving the recovery and use of thermal energy from hot liquid flows which otherwise would be discharged to waste, however, no details of the process or apparatus involved have been released.